The applicant's book entitled "Internal Reflection Spectroscopy", published 1967 by Interscience Publishers (John Wiley & Sons), which is hereby incorporated by reference, describes in detail the development of IRS, its use for material analysis and identification, and includes a detailed description of various kinds of internal reflection elements (IRE) used for establishing the conditions necessary to obtain internal reflection spectra of material samples in solid, liquid or gas phase form. The present invention is directed to a cell attachment primarily for use with liquid samples, that is, a device which includes an IRE for holding a sample and designed to be attached to an existing commercially-available spectrometer for receiving the light beam over a broad spectral range from ultraviolet to the far infrared, direct it into the IRE to the surface supporting the sample, and then redirect the internally reflected attenuated beam back into the spectrometer exactly as it would have entered in the absence of the attachment. The known liquid cells often have shortcomings, such as complexity and general inflexibility. There is a need in the art for a liquid cell for use in IRS characterized by simplicity, minimum components, ease of alignment, precisely mounted mirrors, maintenance of sharp focus, and capable of conducting measurements at room and elevated or reduced temperatures, of thin films, pressurized films, and flow through liquids.